matrixbrute using external audio input (guitar)

[MBLarryH]

In Arturia's tutorial (connectivity) they show him playing an electric guitar thru the MB. I cannot make this work for me. with gate on I get my guitar sound but the external vol in mixer has no effect on sound. Please help with some basic settings to get the external audio input available to be controlled by the MB.

[SoundRider]

Hard to tell, what you did ... so I might only be guessing ...

What do you mean by "exernal vol in mixer has no effect"? Didn't you hear your guitar sound?

If the "audio-input" at the rear panel (check the gain level), the exernal volume, the VCFs, and the VCA is open, you should at least hear the sound of the guitar (maybe you need to press a key too, if the audio-gate is off).

The MB routes the sound to the VCF and then to the VCA section. Both sections need envelopes to come to life and the envelopes need to be triggered. We can use the external input and the "Audio Gate" on the rear panel set to "on" to generate a gate signal from the audio source. This gate signal has to get the envelopes started, which are supposed to modulate the VCFs and the VCA. There is also the "Envelope Follower" in row D of the matrix, which can be additionally used to modulate mod-destinations using the volume of the external signal. We can use any other modulation source too.

I would suggest to start with an init-patch, activate the audio-gate, check that the guitar sound is there, and check the gate signal beeing triggered by picking the strings (well, you could also use the keyboard for the trigger, but that would be a completely different experience), and from there continue as you would do for any other patch.

[ForlornMTL]

Hi all, i just got my first synth and it's the MatrixBrute. (I know, starting big).

I have tried plugging my guitar in and followed (i think), what SoundRider said. But all i can get is a quick sound out, like i pressed a key briefly. And i need to really pluck hard on the strings.
I've played with the Gate, External, Input Gain knobs to no changes whatsoever.
If i press a key and then pluck a string, the string triggers nothing.


Also, if i understand correctly the Enveloppe Follow is what will have my guitar notes "heard" by the MatrixBrute and not always the same note. How do i get that going ?

I know this may seem like an easy thing to most but i am very green here. I'm learning alot from a video series i found but could not wait any longer to get the guitar plugged into it.

Any help for this novice is appreciated.

Thank you for your time.

[SoundRider]

Hi ...

If you hear anything, you are almost there, really

Since this is your first synth, it could be, that you miss a simple thing, which is that the VCF and the VCA need a dedicated ADSR envelope to open and close. If you are hearing a short guitar sound, then it might be that the VCF and VCA envelopes are too short, as simple as this.

Try the following settings for both envelopes. Attack to zero, Decay to max, Sustain to max, and Release to something but not zero. Don't forget to set the "Env 1 Amt"  knob in the filter section clock-wise, let's start, with 3 or 4 o'clock position.

If your guitar sound triggers the gate at all, which I guess it does, this will now trigger the envelopes and the sound should last longer now. The setting is ment for testing only that you have plugged in and set the input sensitivities correctly. Don't expect to experience a "great sound" .

From there you should be able to shape your sound to your liking.

Now, there is a difference between "gate" and "envelope follower".

Gate: This is a simple ON/off trigger, which gets the ADSR envelopes started ... or other things, which can be started oder kept going by a gate-ON signal, like arps or a sequencer.

Envelope Follower: This is a CV-signal, which is generated from an external signal, like your guitar sound, and which can directly be used to control everything, which happens to listen to a CV-signal. We can use an envelope follower CV-signal "instead" or in "combination" with an ADSR.

Hope that shades more light to your MatrixBrute, which is in my view an ideal starting point for a beginning synth enthusiast

[ForlornMTL]

Thank you for the detailed reply.

I am now hearing the sound longer but i still have to be quite brutal with the strings. If i strum the strings nothing happens, but if i pick them hard i get a sound most of the time.
Input Gain is on full, so is External in the mixer.

Maybe i'm not plugged in correctly. I'm going straight from the guitar into the MatrixBrute. Should i have an interface of some sort between them ?

How do i get the MatrixBrute to "follow" my guitar notes ? and not just give me a single note (the last one i pressed on the keyboard).

I wish there was a more profound user manual from Arturia. The leaflet that was in the box barely scratches the surface. Obviously an online manual, no need to have a brick of paper in the box hahahahaha.

Thank you

[SoundRider]

Have you already tried to set the little switch near the input socket from "Line" to "Inst"?

It could be that you have the switch in the "Line" position. If we plug a guitar in, we need the "Inst" position.

As to following the notes of the guitar ... the external input is supposed to run an external signal through the synth only. Since the MB has no module to convert external frequencies to CV, you can not play your guitar like a keyboard controller directly. Such frequency to CV modules exist and could be connected to the CV input controlling the pitch of the MB. There are also modules, which convert guitar sound to MIDI.

BTW ... there is a manual online ... http://downloads.arturia.com/products/matrixbrute/manual/matrixbrute_Manual_1_1_EN.pdf

[ForlornMTL]

I'm green but not that green 
Yes, i've put it to Inst. if set to Line i would not get anything through.
I get it to play but only if i hit the strings real hard, and only momentarily. It cuts out quickly, unlike what the preset is at when i push a key.


This guy says he has a guitar straight into the MB. And you can hear the different notes.

https://youtu.be/i9QRNjn7RwQ

[ForlornMTL]

BTW ... there is a manual online ... http://downloads.arturia.com/products/matrixbrute/manual/matrixbrute_Manual_1_1_EN.pdf

That's exactly what was in the box. I may have been harsh calling it a leaflet. It does say what every knob and button does.
But as a beginner, i would have liked some details or an example of how to get a preset going, from start to finish. Nothing complicated, just the basics.

A user manual should be telling me more than "you can plug your guitar here" with an image of a guitar and then not tell me how to make it work.

The online tutorials are not tutorials, they are "check out what it can do". It does not explain anything. A tutorial is meant to tutor you through a subject. A tutorial on connectivity should tutor me through the process of connecting to the MB.

And as you can see in the Connectivity "Tutorial", he plugs in a guitar and the notes are heard, not just a single note (the last one you pressed on the keys).

https://www.arturia.com/faq/matrixbrute/matrixbrute-tutorials


Maybe i'm not using the proper vocabulary or do not understand what you are trying to tell me about following the guitar notes. But from what i can hear on those videos, the notes are being followed.


I do appreciate the help.

I'm overwhelmed by everything i'm trying to learn all at once to get up to a certain level of understanding the MB.
And i don't mean to sound rude or unappreciative.

It seemed so simple in the video, just plug in and play.

[SoundRider]

You are welcome, no bad vibrations here ...

I have watched the video and the guy tells us that he is using his MB as an effect pedal. That's what I expected.

Just for clarification ... there are synth guitars out in the wild from Roland or Moog, which can be used to control the "pitch" of a synth, or in other words, the pitch of the VCOs. That's what I thought was one of your goals.

If you only want to use the MB as a quite extraordinary sound mangling device for your guitar sound, then this should be easy enough. I just checked it myself again ...

- start with an "Init" patch
- set "auto gate" to ON
- set "external" to INST
- set "external" Gain to near max (clock-wise) ... I used my bass and it blowed the speakers
- set mixer knob for the external signal to max and select at least one filter (it's both off by default)
- set the filter in use max. open

Now plucking a string should engage the envelopes, you will see that the white LEDs flash up and the sound should at least be loud and as long as the envelope 2, which controls the VCA.

If there is no volume, I recommend to check the cable, the guitar volume, or try to use a line-in sound source to check the function of the external input, we never know, there are many options of failure

[DrJustice]

In addition to SoundRider's advice, I can also recommend running without Audio Gate on for when you want the sound to be continuous; just hit Key Hold to let the sound through (VCA env sustain at max). I do this sometimes, using the MxB Mixer level, Drive, Brutefactor, the filters and FX to dial in nice sounds, also adding some modulation including using the envelope follower.

[DrJustice]

Here's an example patch for guitar processing (attachment)

It does several things:
 - The external signal is fed through the ladder filter which uses envelope follower and LFO 1 modulation for the cutoff, also a tiny bit of drive, use any combo External gain, Steiner Drive and Brufefactor to taste for drive/distortion (I calibrate the external input gain on the back of the synth so that there's no clipping with drive and brutefactor at minimum).
 - VCO 1 and 2 makes an FM bubbling sound using the envelope follower to control the VCO 1 and 2 pitches, VCO2 gain is controlled by the envelope follower,  VCO 2 which goes through the Steiner filter, the Steiner cutoff is modulated by LFO 2.
 - The mod wheel can be used to reduce the FM sound by VCO 1 and 2 right down to silence.
 - Macro Knob 4 can be used to turn up a Tremolo effect where LFO 3 controls the VCA.
- The Stereo Delay is in use and LFO 1 modulates the delay time a tiny bit.
- The VCA envelope is set up with full sustain and half release, worth noting if playing with Audio Gate on.

The patch has been saved with  Key Hold, so just hit a key to get the sound coming through and/or use the Audio Gate. The dynamics of the playing will have a big effect on the sound. The key you hit will affect the pitch of the FM sound that VCO 1 and 2 is making. If you set Audio Gate to on, you can use Envelope 1 and 3 for further 'controlled' modulation. Of course the Envelope Follower is the key to playing dependent dynamics here, both with and without Audio Gate.

Since the FM sound is made to be silent when the guitar is silent, it has a limited max volume. With gate on you could crank VCO level 2 much more.

This is just a quick example of some of the things you can do. BTW, if one had en external Pitch to CV Module, then it would be possible to play the oscillators in tune with the guitar with the usual limitations of that method.

Since the MxB is as beastly as it is, you could use synth sounds together with the external input in the same patch, and you could use the sequencer or arepggiator to set patterns of notes and/or modulations to affect the guitar sound. Coupled with a tiny Eurorack for pitch to CV stuff and such, you'd a have quite the bass/guitar electronics heaven

[ForlornMTL]

Thank you both. I think it's moving in the right direction now.
I was able to get more than a quick note through. I tried both of your advise and with the Audio Gate turned Off it was too much to have the continuous sound. Will have to turn some knobs to dial something else that might be more tolerable to my ears.
I'm on headphones.

My brain is fried right now, too much information all week and i looked at the multiple knobs and could not even begin to figure out what to do next. My first week with a synth has been crammed with trying to learn my way around.

Maybe i jumped ahead too quickly and should stick with learning the MxB as a synth keyboard first.

Although i will definitely try your patch DrJustice. Thank you very much for that.

To make a long story short, my 2006 black MacBook is on ios 10.6 and the Arturia software is for 10.8 and up. I need to bring my MxB to the office over the weekend and plug it into Windows 10 to update the firmware so it will be a perfect time to upload your patch.
I have a full weekend already but need to find time for this.

Luckily i bought a Gator case for my MxB today, so it will be much easier to transport. With wheels 

As for a Pitch to CV module. Reading your comment i remembered i also bought a Eurorack with two modules (still in the bag, that i forgot was there ). The salesman said it would be the best way to get my guitar to play through the MxB. But when i saw the videos i went for the direct plugging of the guitar.

I got a Synth Rotek Sequence 8 and a Befaco Instrument Interface.
I probably don't need the Sequence 8 when i think about it now. I was on a mission to find info on making noise...came out with a MxB and a Eurorack. Hahahahaha

I was not forced into buying anything, BTW.
I know the owner of the shop and i worked there one summer. The young synth genius there was very knowledgable and i'm the one who said, give me what i need to get it going right away without having to come back in a week.

Ok, this is getting long winded. Sorry.

Is the Instrument Interface my solution ?

[DrJustice]

...I got a Synth Rotek Sequence 8 and a Befaco Instrument Interface.
...Is the Instrument Interface my solution ?

Well, not really since the MxB has a built in envelope follower and trigger already. The built in envelope follower is also very useful since it has its own row in the mod matrix.

You could of course try that instrument interface module, sending its trigger to the MxB trigger input and its envelope follower and regenerator to the expression pedal inputs. However it wouldn't give you much more functionality than the built in interface. Something like this Analogue systems RS-35 would give you Pitch to CV - just be aware that this style of pitch tracking requires very clean single string playing to get a clean output CV.

[ForlornMTL]

Here's an example patch for guitar processing (attachment)

Wow ! Thank you so much DrJustice. That is exactly what i was looking for. Tried it late Sunday night for a quick check but ended up messing around and getting lost in playing for a good hour.

Hitting any key on the MxB does nothing, no sound. So only the guitar gets the MxB going. How is that ? How could i replicate that ? As that's way better than my first try where i had to have whatever key on the MxB was last pressed as the background to my guitar.

Also, is it me or is the Input Gain working counterclockwise to go up ? I've had it at 90-100% at all times, or so i thought. Yesterday i turned it "down" and finally got the guitar to ring through properly on a basic patch. So it seems, to me, that all the way clockwise is 0 and counterclockwise it 100%. Which is so counter intuitive to me. I never thought of turning it down during my first tries. Now i don't need to pluck the strings like a maniac to hear a half second of the patch.

Well, not really since the MxB has a built in envelope follower and trigger already. The built in envelope follower is also very useful since it has its own row in the mod matrix.

So i have no use for the Eurorack an modules i purchased... will have to see if i can return them or find a buyer.

[DrJustice]

...Hitting any key on the MxB does nothing, no sound. So only the guitar gets the MxB going. How is that ? How could i replicate that ? As that's way better than my first try where i had to have whatever key on the MxB was last pressed as the background to my guitar.

The method used in the patch is to route the Envelope Follower to control the VCO 2 mixer level using one of the assignable matrix columns. That way the VCO 2 volume follows the volume of the guitar sound. The reason for controlling the VCO 2 level directly it like that is so that the patch can be played without using the Audio Gate while still controlling the oscillator level with the guitar sound  - this can be desirable for a continuous sound which captures the full dynamics of the guitar. The patch can also be played using the Audio Gate, but then you may get a bit more gated playing feel, losing the lowest level sounds. Use whichever method works for you and the sound/song.

The basic pitch of the oscillators is taken from whichever key you pressed last, but the FM sound with atonal sweeps and swirls instead of a steady pitch makes it a different feeling from a steady oscillator tuned (or not so well tuned...) to a note.

If you simply don't want any oscillator sound in a patch, turn down all of the VCO 1, 2 and 3 levels in the mixer and/or use the Filter switches to disconnect them from the filter, using only the External signal. As mentioned the mod wheel will fade out VCO 2, so that you only have the guitar sound left. BTW, if you wonder why VCO 2 is the oscillator that's being used in the patch, it's because it's an FM target of both VCO 1 and VCO 3 in the AUDIO MOD section, making it a natural candidate for the carrier when starting out on an FM sound. Note that the actual sound is kind of random, with the patch only being a quick example rather than a finely honed patch...

Also, is it me or is the Input Gain working counterclockwise to go up ?

I think it might just be 


P.S. I'm beginning to wish we had an editor which would make exploring and explaining patches much easier...